Ripples 7/12/18

During the course of summer one notices the waves of different insects that are present at different times.  One might assume that they are present throughout the season, but really their populations ebb and flow during distinct periods, at least for many of them.

photo of monarch butterfly

Monarch butterfly

Like dragonflies, butterflies in all their colors bring another layer of interest to the land.  In early summer a few are around: mourning cloaks, red admirals, American ladies, and eventually some monarchs.  Both of the latter are migratory and recolonize in our area from the south.  The earliest butterflies mate and are then unseen for a while, unless you are lucky enough to find and recognize their caterpillars.  

In mid- summer there are blues, skippers, crescents, swallowtails, sulphurs, wood nymphs, and sometimes unexpected visitors from the south.  The monarchs which arrived in late May immediately began laying eggs on the milkweed they found, and now the next generation of butterflies is appearing and continuing to do the same.

Woodland Dunes has hundreds of acres of what is considered old field- farmland that is no longer cultivated.  Before glyphosate was used in agriculture, common milkweed was considered the most common weed in fields. When the farm fields of our preserves were no longer cultivated, milkweed that was already present expanded it’s coverage.  We have many acres, more than 100 acres today, where milkweed is proving to be a refuge for monarch butterflies. 

Currently, they are seen feeding and mating over almost all the open land in the preserve (during mating the males and females are attached, and the males fly with the females hanging below with wings folded).  There are a number of vantage points where dozens of monarchs can be seen at a time – one is at the overlook for the wetland restoration we did in cooperation with Wisconsin Public Service Corporation a few years ago.  There are a lot of milkweed plants close to the platform and parking area.

There are more monarchs to come. Our area is especially important to them and their reproduction.  In the next six weeks they will allow us to see one of nature’s miracles.  They will continue to reproduce, but the last generation of the year (born in latter August) will begin to migrate to Mexico to a place they’ve never been.  Around Labor Day, when we are enjoying the Kite Festival, monarchs will be streaming southward, following the shoreline of Lake Michigan.  Actually, they start a bit earlier- you’ll notice when all the monarchs seem to be flying to the southwest and this spectacle will continue into October.  I’m sure that just a small fraction of the monarchs make it to their winter refuge, and even those that do face an uncertain future depending on weather and people disturbing their habitat (which is only a few acres in size).  Those that survive will begin their northward flight in late winter and some will reach Texas to start next years generations.  If all goes well, we’ll again see monarchs here next summer.

When you see a monarch, I hope you appreciate all of this, and the value of weeds like milkweed and land left to heal after many years of working for us.  Monarchs, and milkweed, have declined significantly in numbers over the last few decades- not through any bad intentions, but more through lack of understanding of how interrelated the parts of nature are, and how powerful our actions can be.  

I hope as the summer continues, you find a bit of joy and wonder in every monarch you see.

photo- monarch butterfly at Woodland Dunes by Nancy Nabak


Jim Knickelbine
Executive Director
Woodland Dunes Nature Center and Preserve

Ripples 7/5/18

photo of ebony jewelwing

ebony jewelwing

The progression of the summer season is very much evident now.  Although birds are still singing with as much enthusiasm as a month ago, many are already tending to young that have left the nest, or are raising a second brood.  At the feeders, young cardinals and house finches beg for food from their parents while young robins dot the landscape of lawns and shrubs.  Early blooming shrubs are already setting fruit, just in time for birds to help them distribute their seeds to new places.  At our headquarters, many birds are eyeing-up the big mulberry tree, the most effective bird feeder we have.  The young ospreys are growing by leaps and bounds, keeping their father busy catching and hauling fish to the nest.  Two of the three eggs they tended hatched, which is fine for the pair of young.  They will receive plenty of attention and fishy meals.

Coreopsis and spiderwort and mints are blooming in the meadows, along with milkweed.  Along with the wildflowers, insects are starting to come into their own now.  Among those milkweeds we are seeing many monarch butterflies, and finding many eggs and caterpillars.  I wish they had more protected places like ours.  Other butterflies are evident now- blues and skippers, swallowtails and sulphurs, all adding their color to the summer landscape.  Even more numerous are the moths and beetles of all sorts shiney like tiny jewels.  Except for the rose chafers and Japanese beetles perhaps, as they are alien jewels we’d rather not see.

A couple of weeks ago one only saw the large bumblebee queens, but now the smaller workers, looking like miniature versions of their royal mothers, dot the flowers in our gardens – their pollen baskets, or corbicula, on their back legs overflowing with protein-packed granules to be brought back to their nests.  One can’t survive on nectar alone, it turns out, and the bees have developed a wonderful way to convey what they need back to their families.

Especially noticeable around water, are the dragonflies.  I use the term meaning to include all those in that group – damselflies, clubtails, and all forms of these beautiful and impressive insects.  Right now, just a few feet from the beginning of Cattail Trail, there are many different species, including bluets (little blue damselflies of some sort), whitetails, twelve-spotted skimmers, pondhawks, and black, and red saddlebags (which might be a Carolina saddlebag). In the algae growing in the pond are many dragonfly larvae or nymphs, and new species are constantly emerging.  In younger days I didn’t pay much attention to dragonflies save the bluets and the common green darner, a migratory species.  Over the years, although I am just barely familiar with them, I have become more aware of the many different species that we are blessed with.

The dragonflies are predators, and seem to spend their adult lives mainly eating or reproducing.  They will fly right up to you and snatch a mosquito or deerfly buzzing around your head with amazing speed.  They locate a mate and attach themselves, reproducing on the fly, often laying eggs on vegetation in the water.  Their nymphs hatch and grow, spending most of their lives below surface until emerging next year at just the right time to find a mate of their kind.

There are more and more people becoming interested in the dragonflies- there is a Wisconsin Dragonfly Society whose members help each other with tricky identifications of species, the sorting of which can be amazingly subtle and complex.  And although I’m afraid I will never be an expert on dragonflies, their presence, along with the birds and mammals, insects and wildflowers of our Lakeshore, seems to make our world more complete.

photo- an ebony jewelwing damselfly, the author’s favorite species

Jim Knickelbine
Executive Director
Woodland Dunes Nature Center and Preserve

Ripples 6/28/18

Suddenly, it’s midsummer.  Of all the seasons, the midsummer period never fails to catch me by surprise- where did spring and early summer go?  Fall perhaps progresses as rapidly, and midwinter and early spring seem to crawl.  The life of the forest, which a month ago seemed a little sparse, is now building in abundance and diversity.  Many baby birds are already fledged, and fawns follow their mothers about experiencing the world for the first time.  Mother possums labor along, literally covered with their young.  Their work, like that of all mothers, is never done.

The transition from day to night is just as interesting as the dawn.  Many wild species have the good sense to avoid the harshness of midday and its heat, and a different world reveals itself at dusk.  Some birds sing different songs at these transitional times, some become more active, and some find safe places to roost.  In the daylight, swallows and swifts chase down insects on the wing, but at dusk, if one is fortunate, one might witness nighthawks taking over those activities, but there aren’t as many as there used to be.  Bats too take the place of the swallows at night- in that ingenious way they are able to use the same habitat without competing, separated by time rather than distance.  And, too, there are different insects present in the air at different times of day and night- recently researchers have found that some of the night-flying insects have the ability to mimic and therefore “jam” the locating sounds that bats produce.  This aerial dance of life and death continues 24 hours a day, and its amazing how many interactions in nature take place above the ground, unseen by us.

photo of a firefly

firefly

If insects of the bloodthirsty sort allow us to observe the transition, dusk is an amazing time to be out.  When I was young, summer vacation meant the opportunity to be outside all the time, but the cool, damp of dusk was wonderful.  We pitched horrible musty canvas pup tents with no floors and enjoyed every minute of our camp-outs.  As it became darker the world became more mystical, especially when the little green lights of fireflies appeared first in the grass, then one by one rose into the air.  We’d catch some with our hands and put them in mason jars, and they were our tent night-lights, to be released in the morning when the sun beating on the canvas made it unbearably warm.  I didn’t know then that there were more than one kind of firefly, in fact three genera of them- Photinus, Photuris, and Pyractomena, or that the light from fireflies can come in greenish, blue-green, or yellow colors.  Or that the larvae of fireflies are fierce predators of other insects and that some adults mimic the flashes of their cousins so as to lure and dine on them.

Through the night we would hear the sounds of the green frogs by the river, a barred owl, a whip-poor-will, a startled deer, and the never-ending hum of mosquitoes who invited themselves into our screenless shelters.  A lot of the time, I don’t think we really attempted to sleep- it was far too much fun to be with friends outside on a delicious summer night.  And although we were unaware of the science behind what we saw and heard, the outside world of a midsummer’s night was just about as magical as Shakespeare imagined it to be.

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photo attached- a firefly from wikipedia

Ripples 6/21/18

Ripples from the Dunes, written by Jay MacKenzie, Woodland Dunes summer intern

During one of my first days as an intern at Woodland Dunes Nature Center, I was out at the Manitowoc Lakefront Birding Area helping staff members water and mulch some native trees and shrubs that they had previously planted.  As the name suggests, there were a variety of birds active in the area, from flocks of nesting gulls to purple martens.  I have almost no experience as a birder, so I was relying on the staff members to point out the calls and defining characteristics of the species we saw.  

photo of a killdeer in distraction display

Killdeer in distraction display

At one point, we saw a medium-sized, tawny brown-and-white bird with long legs hopping along the ground.  Jim, Woodland Dunes’ Executive Director, identified it as a killdeer – a species that I had not heard of previously.  We began to walk toward the bird to get a better look.  As we approached, the killdeer raised its wings.  I thought it was about to fly away, but instead, it began to walk around while emitting a loud, shrill call.  Jim explained that this killdeer was actually performing a distraction display – a behavior intended to distract a potential predator from its nest.  Killdeer lay their eggs on the ground and we were probably walking directly toward this bird’s nest.  It perceived us as predators, and was attempting to lead us away from its clutch.  

Abnormally positioned wings and distress calls mimic a wing injury, and thus signal an easy meal for a would-be egg thief.  Once the predator notices this and begins to pursue its dinner, the bird leads it away from its nest before suddenly “healing” and flying away.  We retreated from the killdeer, not wanting to disturb its nest.  However, I was impressed by this clever nest defense strategy and wanted to learn more.

Distraction displays are not limited to killdeer, or even to nesting birds.  Even though they are most common in birds, they have been observed in fish and mammal species as well.  Displays can take a variety of forms.  Plovers, a family of wading birds of which the killdeer is a member, are known for their use of “false brooding” displays in which the plover crouches and broods on a non-existent nest, drawing predators away from the location of the real nest.  Plovers, along with other types of birds, can also distract predators by ruffling their feathers, crouching and running away from their nest to mimic the flight response of a small rodent.  Killdeer are the most well-known practitioners of the “broken wing” display.

It’s obvious that the ability to lure predators away from vulnerable eggs or juveniles gives an adaptive advantage in the form of reduced infant mortality.  However, it is much less obvious how such apparently sophisticated behaviors could have evolved in animals that are not generally known for their cleverness.  One theory is that they arose as a instinctual fear response to the presence of a predator.  In species experiencing heavy predation pressure, a fear response that happened to distract predators would reduce predation and cause that specific response to undergo positive selection.  

Another theory is that distraction displays are the result of a nesting bird’s conflicting instinctual impulses to at once attack the predator, protect its young and escape the threat.  Through a process known as displacement, an animal experiencing such conflicting stressors may initiate an irregular “intermediate” behavior in response.  If this displacement behavior happened to distract predators, it would undergo positive selection.  Whatever the origin of distraction displays, they are fascinating examples of animal’s abilities to adopt ingenious and unexpected solutions to the problems they face.

photo of a killdeer doing a distraction display, taken by Nancy Nabak

Ripples 6/14/18

So often the things right under our nose don’t get the attention they deserve until they are seen in a different way.  This realization happens every year at this time when we travel all parts of our preserve to conduct summer bird surveys.  These surveys have been done for more than 40 years each June after the spring migration has ceased, usually starting June 10. 

Initially, 11 routes were walked, on and off-trail, and every bird seen or heard was counted.  Due to restraints on our time, and in an effort to make the data more useful, we have established 28 points throughout the main preserve in easily locatable places. These are visited for 10 minute periods.  Most birds are heard but not seen, thanks to the thick foliage on trees and shrubs. One of the wonderful things about birds is that their songs are often loud and distinct, so they can be detected under such conditions.

photo of Canada warbler

Canada warbler

There are two times of day when the world seems truly magical- dawn and dusk- and being outdoors at those times allows us to experience a different world.

The preserve in early morning is hazy and often still, with lush green leaves all around and wildflowers below.  It is anything but quiet- after a night’s rest birds are ready to advertise the location of their territories and their fitness as both a defender of that space and as a mate. 

That they all sing simultaneously makes doing surveys challenging sometimes.  While birds probably don’t care that much about the songs of other species, we frantically try to record each of them.  Some songs are much louder than others. For some, great volume is apparently not required to get one’s point across to others of its kind.  All the calls are noted during the 10 minute count period.  Thanks to technology, the species can be recorded using an app on a cellphone and the data immediately archived. 

And so we travel through this mysterious world noting the music produced by those who live here.  On our first day this year, counting five points, we encountered 29 species, including such lovely and seldom noticed bird as the veery, blue-gray gnatcatcher, mourning and Canada warblers, and the Red-shouldered hawk. The last two species are considered of greatest conservation need. 

To be surrounded by such unusual wildlife in such a wonderful setting is better than any nature documentary. To immerse yourself in this world is good for you in probably more ways than we realize.  And then there are the other wildlife encounters – a mother possum covered with her clinging young, a curious doe, the occasional fox (red or gray), which glides silently through the forest and into our morning experience.

These surveys take some effort and forebearance- getting up early is not easy, and mosquitoes can be hungry, but being there is worth it.  Typically, 100 or so species of birds is recorded in the Woodland Dunes preserve, a reflection of the special place that it is.  The species list has changed over the years and that bears watching.

There are 23 points yet to be counted for this year, so a few more early mornings are in order.  Coffee works great to get the morning started, and the wonders of the preserve will keep us going as we document the amazing wildlife of our Lakeshore. 

photo: wikipedia